This weekend marks the 15th annual Great Backyard Bird Count, a four-day event that makes "citizen scientists" out of bird watchers and nature lovers across North America. The campaign is part of a broad effort to keep tabs on the continent's bird populations, using volunteers of all ages and backgrounds to supplement more formal research.

The 2012 GBBC lasts from Friday, Feb. 17, through Monday, Feb. 20, and anyone can participate. All you have to do is spend at least 15 minutes this weekend counting every individual member of each bird species you see, and then report your findings online. The GBBC recommends looking at a regional bird checklist first, "to get an idea of the kinds of birds you're likely to see in your area in February."

The event — a joint project of the National Audubon Society, the Cornell Lab of Ornithology and Bird Studies Canada — yields far more data than professional scientists could muster on their own. During the 2011 GBBC, for instance, volunteers submitted some 92,000 checklists, totaling more than 11 million bird observations from 596 different species. These kind of data are especially important now, as climate change disrupts many bird species' long-established behavior patterns, explains Cornell Lab of Ornithology director John Fitzpatrick in a press release:

"This is a very detailed snapshot of continental bird distributions. Imagine scientists 250 years from now being able to compare these data with their own. Already, with more than a decade of data in hand, the GBBC has documented changes in late-winter bird distributions."

Data from the bird count help scientists investigate a wide range of issues related to avian conservation, including local bird diversity, regional population trends, and vulnerability to environmental threats like West Nile virus or air pollution.

And the 2012 GBBC could be particularly helpful, organizers point out, in revealing how this unusually warm winter has affected birds' migration habits. Snowy owls, for example, have recently been flying south from the Arctic in record numbers — so keep an eye out for one if you decide to go bird-counting this weekend.

Snowy owl (Photo: ZUMA Press)

The GBBC is one of several crowd-sourced bird counts held throughout the year, including the Christmas Bird Count, Project FeederWatch and eBird. But while such events help scientists study birds, mass data collection isn't their only benefit. As Audubon chief scientist Gary Langham points out in a press release, bird counts are also a good way to get people more interested in and connected with nature:

"This count is so much fun because anyone can take part — we all learn and watch birds together — whether you are an expert, novice or feeder watcher. I like to invite new birders to join me and share the experience."

Despite the name, you shouldn't necessarily feel confined to your yard for the Great Backyard Bird Count. There are two ways to participate: a stationary count, in which you stay in one place to count birds (like your yard), or a traveling count, in which you count birds while covering a distance (like hiking a trail). The former is the classic GBBC method, but the latter is reportedly becoming more popular, especially as a social outing for birding clubs and other groups. If you opt for the traveling count, just be careful not to count the same individual birds more than once.

Northern cardinal (Photo: Jen Goellnitz/Flickr)

Spending time in the woods and other natural, undeveloped areas has been linked to psychological benefits in humans, but urban and suburban bird counts are no less important. In fact, they can be even more important in some instances, revealing how birds are adapting to human-related dangers like habitat loss or housecats. Either way, simply flocking toward birds might provide its own cognitive boost — researchers in the U.K. are currently studying whether listening to birds' songs can improve a person's mood, attention and even creativity.

And if you feel a surge of creativity while counting birds this weekend, consider channeling it through your camera. Event organizers are once again hosting their annual GBBC photo contest; anyone can submit bird photos that fall into one of six categories (overall, behavior, composition, group, habitat, people). You could win from a wide range of prizes, including bird feeders, binoculars, books and even an Apple iPod Touch preloaded with Audubon guides.

See the GBBC website for more info, or check out this list of local events.

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Russell McLendon ( @russmclendon ) writes about humans and other wildlife.